On 2/9/22 16:21, Thomas Zimmermann wrote: [snip] >> >> It could be taken from this patch-set anyways if someone wants to wire the >> needed support for R8. > > I think, policy is to not keep unused code around. > Ok, I'll drop it then. We can include it again when adding R8 formats. [snip] >>> If might be faster to allocate both buffers in one step and set the >>> pointers into the allocated buffer. >>> >> >> Not sure I got this. Do you mean to have a single buffer with length >> linepixels + len_src32 and point src32 and gray8 to the same buffer ? > > That's the idea. I don't know the exact overhead for kalloc(), but at > least the in userspace, malloc() in hot code paths is not a good idea. > There's usually some searching for free space involved. > Sure, let's do it in one allocation then and I'll add some comments to make easier for people to follow the code. > In the long term, we could add a field in struct drm_framebuffer to keep > such buffers around for reuse. > >> >>>> + >>>> + /* >>>> + * For damage handling, it is possible that only parts of the source >>>> + * buffer is copied and this could lead to start and end pixels that >>>> + * are not aligned to multiple of 8. >>>> + * >>>> + * Calculate if the start and end pixels are not aligned and set the >>>> + * offsets for the reversed mono line conversion function to adjust. >>>> + */ >>>> + start_offset = clip->x1 % 8; >>>> + end_offset = clip->x2 % 8; >>> >>> end_len, again. If you have 1 single bit set in the final byte, the >>> offset is 0, but the length is 1. >>> >> >> Agreed, will change it too. > > Feel free to add my > > Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx> > Thanks! Best regards, -- Javier Martinez Canillas Linux Engineering Red Hat
